POST AND METHOD OF PROVIDING A POST

Abstract

A method of providing a post includes providing an inner member, and providing an outer tubular layer of polymer or plastic around the inner member, the outer tubular layer including an outer surface having a surface roughness Ra of at least 3 m. A post is also provided.

Claims

1. A method of providing a post, the method comprising: providing an inner member; and providing an outer tubular layer of polymer or plastic around the inner member, the outer tubular layer comprising an outer surface having a surface roughness Ra of at least 3 m.

2. The method according to claim 1, wherein the method comprises modifying the surface roughness of the outer surface to the surface roughness Ra of at least 3 m while the outer tubular layer is provided around the inner member.

3. The method according to claim 1, wherein the method comprises modifying the surface roughness of the outer surface to the surface roughness Ra of at least 3 m by wrapping a sheet onto the outer surface prior to consolidation of the outer tubular layer, and removing the sheet from the outer surface after consolidation of the outer tubular layer.

4. The method according to claim 3, wherein the sheet comprises a peel ply sheet.

5. The method according to claim 3, wherein the sheet is wrapped substantially helically onto and around the outer surface.

6. The method according to claim 1, wherein the method comprises modifying the surface roughness of the outer surface to the surface roughness Ra of at least 3 m by machining, knurling and/or blasting of the outer surface.

7. The method according to claim 1, providing the inner member comprises winding the inner member by means of filament winding.

8. The method according to claim 1, wherein providing the outer tubular layer comprises winding the outer tubular layer around the inner member.

9. The method according to claim 1, wherein the inner member comprises a tubular layer.

10. The method according to claim 1, wherein the inner member comprises fiber-reinforced polymer or fiber-reinforced plastic.

11. A post, comprising: an inner member; and an outer tubular layer of polymer or plastic around the inner member; wherein the outer tubular layer comprises an outer surface having a surface roughness Ra of at least 3 m.

12. The post according to claim 11, wherein the inner member comprises a tubular layer.

13. The post according to claim 11, wherein the inner member comprises fiber-reinforced polymer or fiber-reinforced plastic.

14. The post according to claim 11, wherein the post comprises a utility pole.

15. A method of providing a post, the method comprising: providing an inner member; providing an outer tubular layer of polymer or plastic around the inner member; and imprinting a surface structure on an outer surface of the outer tubular layer to provide a surface roughness Ra of the outer surface of the outer tubular layer of at least 3 m.

16. The method of claim 15, wherein the outer tubular layer comprises a thermoplastic, the method further comprising curing the thermoplastic after imprinting the surface structure on the outer surface of the outer tubular layer.

17. The method according to claim 15, wherein imprinting the surface structure on the outer surface of the outer tubular layer comprises wrapping a sheet onto the outer surface prior to consolidation of the outer tubular layer, and removing the sheet from the outer surface after consolidation of the outer tubular layer.

18. The method according to claim 17, wherein the sheet comprises a peel ply sheet.

19. The method according to claim 17, wherein the sheet is wrapped substantially helically onto and around the outer surface.

20. The method according to claim 15, wherein imprinting the surface structure on the outer surface of the outer tubular layer is performed while the outer tubular layer is provided around the inner member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Further details, advantages and aspects of the present disclosure will become apparent from the following embodiments taken in conjunction with the drawings, wherein:

[0032] FIG. 1: schematically represents a side view of production of an inner member of a post;

[0033] FIG. 2: schematically represents a side view of the produced inner member;

[0034] FIG. 3: schematically represents a side view of production of an outer tubular layer of the post;

[0035] FIG. 4: schematically represents a side view of a sheet wrapped around the outer tubular layer;

[0036] FIG. 5: schematically represents a side view of a post after removal of the sheet from the outer tubular layer;

[0037] FIG. 6: schematically represents an enlarged view of section A in FIG. 5;

[0038] FIG. 7: schematically represents a perspective view of the post; and

[0039] FIG. 8: schematically represents two posts supporting overhead power lines.

DETAILED DESCRIPTION

[0040] In the following, a method of providing a post and a post, will be described. The same reference numerals will be used to denote the same or similar structural features.

[0041] FIG. 1 schematically represents a side view of production of an inner member of a post. The inner member is produced by means of conventional filament winding. A plurality of wet filaments 10 are wound around a mandrel 12. As shown in FIG. 1, the filaments 10 are wound helically in several layers. In this example, the filaments 10 are of a glass fiber-reinforced thermosetting polymer. Thus, the post provided by the method is a composite post.

[0042] FIG. 2 schematically represents a side view of the produced inner member 14. The inner member 14 is formed as a tube comprising a plurality of layers of glass fiber-reinforced thermosetting polymer. Furthermore, the inner member 14 in FIG. 2 is tubular with a constant thickness and a constant inner diameter. However, the thickness does not have to be constant.

[0043] FIG. 3 schematically represents a side view of production of an outer tubular layer 16 of the post. In this example, the outer tubular layer 16 is formed around the inner member 14 by winding a thermoplastic tape 18 onto the inner member 14 to form the post 20. In this example, the thermoplastic tape 18 is made of polyethylene. The thermoplastic tape 18 may be pretreated with corona, plasma, etching or open flame treatment. Glue may optionally be provided between the inner member 14 and the outer tubular layer 16. The winding of the thermoplastic tape 18 is continued until a desired thickness of the outer tubular layer 16 has been obtained. FIG. 3 further shows an outer surface 22 of the outer tubular layer 16. The thermoplastic tape 18 and the filaments 10 are wound by the same machine (not shown).

[0044] FIG. 4 schematically represents a side view of a sheet 24 wrapped around the outer tubular layer 16 in a process of modifying a surface roughness of the outer surface 22 of the outer tubular layer 16. In this example, the sheet 24 is a thermally shrinking peel ply sheet wrapped helically around the outer tubular layer 16. As the sheet 24 is wound around the outer tubular layer 16, air is forced out of the outer tubular layer 16. The sheet 24 has a certain roughness that will be imprinted in the outer surface 22 of the outer tubular layer 16.

[0045] The sheet 24 is wrapped around the outer tubular layer 16 before the outer tubular layer 16 has consolidated. As the sheet 24 is pressed onto the outer surface 22, the surface texture of the sheet 24 is printed into the outer surface 22 during consolidation of the outer tubular layer 16. The sheet 24 is wound by the same machine (not shown) as having wound the thermoplastic tape 18 forming the outer tubular layer 16 and the filaments 10 forming the inner member 14.

[0046] The outer tubular layer 16 with the wrapped sheet 24 is then cured. By keeping the sheet 24 wrapped around the outer tubular layer 16, it can be ensured that the thickness of the outer tubular layer 16 remains static around circumference of the inner member 14 during consolidation.

[0047] FIG. 5 schematically represents a side view of the post 20 after removal of the sheet 24 from the outer tubular layer 16. FIG. 6 schematically represents an enlarged view of section A in FIG. 5. With collective reference to FIGS. 5 and 6, when the sheet 24 is removed after consolidation of the outer tubular layer 16, a coarse texture is exposed on the outer surface 22 of the outer tubular layer 16. In this way, the outer surface 22 of the outer tubular layer 16 is provided with a surface roughness Ra of at least 3 m, such as 10 m, expressed as the arithmetic mean deviation of the profile of the outer surface 22. Due to this surface roughness, an increased friction is provided on the outer surface 22. The surface roughness of the outer surface 22 of the outer tubular layer 16 has thus been modified while the outer tubular layer 16 was provided around the inner member 14.

[0048] FIG. 7 schematically represents a perspective view of the manufactured post 20. The post 20 in this example is a utility pole. The post 20 is made up of the inner member 14 and the outer tubular layer 16 provided around the inner member 14.

[0049] The inner member 14 and the outer tubular layer 16 have the same length along a longitudinal axis 26 of the post 20, although the inner member 14 is illustrated as protruding from the outer tubular layer 16.

[0050] As shown in FIG. 7, the outer surface 22 forms the outermost surface of the post 20. The outer tubular layer 16 forms a protective layer around the inner member 14.

[0051] In this example, the thickness of the inner member 14 is larger than the thickness of the outer tubular layer 16. However, the respective thickness of the inner member 14 and the outer tubular layer 16 may be varied.

[0052] FIG. 8 schematically represents two posts 20 supporting overhead power lines 28. The outer surface 22 of the outer tubular layer 16, having a surface roughness Ra of at least 3 m, provides a rough surface texture that can be utilized for climbing the post 20, e.g. by means of a generic safety sling, to access the power lines 28. Thereby, the post 20 according to the present disclosure can be climbed in the same way as a wood post. The outer surface 22 of the outer tubular layer 16 further improves the grip of the post 20 in the ground. For example, the resistance against rotational torques acting around the longitudinal axis 26 of the post 20, is increased.

[0053] While the present disclosure has been described with reference to exemplary embodiments, it will be appreciated that the present invention is not limited to what has been described above. For example, it will be appreciated that the dimensions of the parts may be varied as needed. Accordingly, it is intended that the present invention may be limited only by the scope of the claims appended hereto.